1. Background of the Invention
The invented methods are directed to the detection and identification of the source of a water problem in a house, building or other structure. The invented methods are further directed to the detection of mold and fungi which inhabit moist predetermined areas of structures, and which can pose health concerns to persons living or working in their presence.
2. Description of the Related Art
The presence of a water problem in a structure is often difficult to detect before damage becomes so extensive that it is apparent to the unaided eye. In many cases, water seeps inside of a wall, ceiling, floor, roof or foundation of a structure such as a building or house, and causes widespread damage before the problem is noticeable. By the time the water damage is visible, repairs to fix the structure are often far more costly than they would be if the water problem could be detected at an earlier stage. It would therefore be desirable to detect the presence of a water problem in a structure at a relatively early stage in its development so that such problem may be more readily corrected, possibly at greatly reduced expense.
In addition, numerous home and building owners have incurred the expense and inconvenience of repeatedly repairing a structure in an effort to correct a water problem, only to find the same problem recurring after repairs are made. It would be desirable to detect the presence of moisture in a structure, even in areas not visible to the unaided eye, to properly identify the source of a water problem so that effective repair measures can be used to correct the water problem.
Another problem that is related to this invention concerns the limited area covered by most conventional moisture-detection devices such as capacitance meters. More specifically, the coverage predetermined area of such devices is generally less than one-hundred centimeters. The use of such devices to detect moisture in a structure containing hundreds to many thousands of square meters is clearly impractical. It would be desirable to provide a method capable of detecting moisture in relatively large areas of a structure with less need to reposition moisture detection equipment used to scan such areas. It would also be desirable to provide the capability to detect moisture in relatively large areas of a structure so that inspection of a structure can be performed more rapidly than is possible with conventional devices and techniques.
Apart from the damage caused by water directly by rotting or otherwise deteriorating the material composing a structure, the presence of water in a structure can lead to many other problems. For example, pests such as termites are attracted to moist wood in structures. Termites are capable of undermining a structure in a short period of time. The detection of a water problem in a structure, even if latent, would therefore be beneficial to stop or prevent pest infestation in a structure. Other problems associated with the presence of moisture in a structure include the so-called xe2x80x9csick homexe2x80x9d syndrome. More specifically, moist and dark areas of a structure such as a house or building often provide environments conducive to growth of fungi or molds to which many persons are allergic. Numerous instances have been reported in which persons living in houses or working in buildings have been made ill by fungi growing in the structure, in some cases resulting in death. In an effort to correct a water problem involving Fungi, some building owners have spent in excess of the original building cost. It would therefore be desirable to detect and correct a water problem not only to prevent damage caused directly by water in a structure such as by rotting, but also to allow detection and correction of such problem to eliminate the indirect consequences of a water problem, such as pest or mold and fungi infestation.
Also related to the present invention is the general field of spectroscopy. Spectroscopy is basically the study of how electromagnetic radiation interacts with matter. Generally speaking, spectroscopy can be performed in one of two techniques. In the first technique, a substance is exposed with electromagnetic radiation generally with a broad spectrum of wavelengths. The substance will absorb electromagnetic radiation energy at discrete wavelengths which are highly indicative of the identity of the substance, particularly if its atomic structure is relatively simple. An unknown substance can therefore be identified by exposing the substance with a broad spectrum of electromagnetic radiation wavelengths and determining those wavelengths at which the substance absorbs electromagnetic radiation energy, i.e., its absorption spectra. The second technique involves the excitation of a substance with electromagnetic radiation or other form of energy. The substance can absorb the electromagnetic radiation and be brought to an excited state. Upon returning to its ground state, the substance emits radiation at certain discrete wavelengths that are highly characteristic of the substance. An unknown substance can therefore be identified by its emission spectra. The emission wavelengths of a substance generally closely correspond to its absorption wavelengths, but will generally also include additional wavelengths that are not included in the substance""s absorption spectrum. While spectroscopy is a useful science and has been used widely in many different applications, its use relative to structures such as a building or house to detect a water problem, substances that indicate the source of the water problem, or mold and fungi, has not been known.
An object of the invention is to detect the existence of a water problem in a structure.
Another, more specific object of the invention is to detect a water problem in a structure at a relatively early stage, even if the problem is latent, so that the water problem can be corrected before the structure incurs relatively extensive damage requiring costly repairs.
A further object of the invention is to correctly identify the source of a water problem in a structure to permit appropriate corrective action and/or repairs to be made to fix the problem.
An additional object of the invention is to sense the presence of water over a relatively large area of the structure to reduce the need to reposition testing equipment and to permit the structure to be scanned in a relatively rapid manner.
Another object of the invention is to effectively detect and identify the source of a water problem so that such problem can be corrected to reduce likelihood of infestation by termites or other pests, or molds or other fungi.
A further object of the invention is to effectively detect and identify the presence of mold or fungi in a structure.
The present invention overcomes the above-noted disadvantages, and attains the objects and advantages set forth above. Broadly stated, the method of the invention comprises exposing an area of a structure with electromagnetic radiation including at least one exposure wavelength significantly absorbed by water, at least one exposure wavelength significantly absorbed by water vapor, and at least one reference wavelength not significantly absorbed by water or water vapor. The method also comprises sensing the radiation at the exposure wavelength significantly absorbed by water, the exposure wavelength significantly absorbed by water vapor, and the reference wavelength not significantly absorbed by water and water vapor. The method further comprises determining whether water is present in the exposed area of the structure based on the sensing. The exposure and reference wavelengths can be such as not to be absorbed significantly by the material composing the structure. The exposure wavelengths for water and water vapor can be predetermined to be wavelengths that are related but shifted in wavelength by the transition of water between liquid and gas phases. The exposure wavelengths for water and water vapor can comprise about 0.97 microns and 0.935 microns, 1.2 microns and 1.13 microns, 1.45 microns and 1.38 microns, and 1.94 microns and 1.86 microns, respectively. The reference wavelength for water and water vapor can comprise at least one wavelength of about 1.06 microns and 1.66 microns. Furthermore, the reference wavelengths for water and water vapor can be the same wavelength.
These together with other objects, features and advantages of the invention will become subsequently apparent, and reside in the details of construction and operation as more fully hereinafter described and claimed, reference being made to the accompanying drawings, forming a part hereof wherein like numerals refer to like parts throughout the several views.